CONSOLIDATED STATEMENTS OF CHANGES IN CAPITAL OF ERP OPERATING LIMITED PARTNERSHIP - USD ($) $ in Thousands	Total	ERPOP [Member]	PREFERRED SHARES ERPOP [Member]	General Partner [Member] ERPOP [Member]	Limited Partner ERPOP [Member]	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) ERPOP [Member]	DISTRIBUTIONS [Member] ERPOP [Member]	PARTIALLY OWNED PROPERTIES [Member] ERPOP [Member]
Balance, beginning of year at Dec. 31, 2020			$ 37,280	$ 10,532,037	$ 233,162	$ (43,666)
Balance, beginning of year at Dec. 31, 2020								$ 4,673
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				74,063	(74,063)
Exercise of EQR share options				85,445
EQR's Employee Share Purchase Plan (ESPP)				4,265
EQR restricted shares				8,389
EQR share options				3,101
EQR ESPP discount				991
Net income available to Units - General Partner		$ 1,329,760		1,329,760
OP Units - General Partner distributions				(902,412)
Offering costs				(428)
Supplemental Executive Retirement Plan (SERP)				(1,335)
Change in market value of Redeemable Limited Partners				(158,598)
Losses reclassified into earnings from other comprehensive income	$ 9,394	9,394				9,394
Equity compensation associated with Units - Limited Partners					17,797
Net income available to Units - Limited Partners		45,900			45,900
Units - Limited Partners distributions					(30,612)
Change in carrying value of Redeemable Limited Partners					(1,428)
Adjustment for Limited Partners ownership in Operating Partnership				(23,338)	23,338
Distributions declared per Unit outstanding							$ 2.41
Net income attributable to Noncontrolling Interests	1,396,714	1,396,714						17,964
Contributions by Noncontrolling Interests								1,394
Distributions to Noncontrolling Interests								(5,865)
Balance, end of year at Dec. 31, 2021			37,280	10,951,940	214,094	(34,272)
Balance, end of year at Dec. 31, 2021								18,166
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				11,923	(11,923)
Issuance of OP Units				139,623
Exercise of EQR share options				25,069
EQR's Employee Share Purchase Plan (ESPP)				4,178
EQR restricted shares				11,595	1
EQR share options				2,321
EQR ESPP discount				796
Net income available to Units - General Partner		773,821		773,821
OP Units - General Partner distributions				(942,047)
Offering costs				(783)
Supplemental Executive Retirement Plan (SERP)				(269)
Acquisition of Noncontrolling Interest - Partially Owned Properties				(27,383)
Change in market value of Redeemable Limited Partners				176,490
Unrealized holding gains (losses) arising during the year	20,654	20,654				20,654
Losses reclassified into earnings from other comprehensive income	11,071	11,071				11,071
Equity compensation associated with Units - Limited Partners					19,104
Net income available to Units - Limited Partners		26,310			26,310
Units - Limited Partners distributions					(30,407)
Change in carrying value of Redeemable Limited Partners					4,214
Adjustment for Limited Partners ownership in Operating Partnership				11,432	(11,432)
Distributions declared per Unit outstanding							2.50
Net income attributable to Noncontrolling Interests	806,995	806,995						3,774
Contributions by Noncontrolling Interests								603
Distributions to Noncontrolling Interests								(18,469)
Acquisitions of Noncontrolling Interests - Partially Owned Properties								(4,795)
Balance, end of year at Dec. 31, 2022			37,280	11,138,706	209,961	(2,547)
Balance, end of year at Dec. 31, 2022								(721)
Conversion of OP Units held by Limited Partners into OP Units held by General Partner				23,948	(23,948)
Exercise of EQR share options				23,632
EQR's Employee Share Purchase Plan (ESPP)				3,517
EQR restricted shares				12,486	1
EQR share options				4,628
EQR ESPP discount				644
OP Units repurchased and retired				(49,105)
Net income available to Units - General Partner		832,348		832,348
OP Units - General Partner distributions				(1,004,904)
Supplemental Executive Retirement Plan (SERP)				32,078
Acquisition of Noncontrolling Interest - Partially Owned Properties				(900)
Change in market value of Redeemable Limited Partners				7,667
Unrealized holding gains (losses) arising during the year	4,514	4,514				4,514
Losses reclassified into earnings from other comprehensive income	3,737	3,737				3,737
Equity compensation associated with Units - Limited Partners					16,430
Net income available to Units - Limited Partners		26,710			26,710
Units - Limited Partners distributions					(30,107)
Change in carrying value of Redeemable Limited Partners					21,358
Adjustment for Limited Partners ownership in Operating Partnership				18,099	(18,099)
Distributions declared per Unit outstanding							$ 2.65
Net income attributable to Noncontrolling Interests	$ 868,488	$ 868,488						6,340
Contributions by Noncontrolling Interests								9
Distributions to Noncontrolling Interests								(5,818)
Acquisitions of Noncontrolling Interests - Partially Owned Properties								(2,837)
Consolidation of previously unconsolidated entities								4,021
Balance, end of year at Dec. 31, 2023			$ 37,280	$ 11,042,844	$ 202,306	$ 5,704
Balance, end of year at Dec. 31, 2023								$ 994